# Science

1. science
Why can't we see a new moon?
2. Science
The combined resistance of two identical resistors connected in series is 8 ohm. Their combined resistance in a parallel arrangement will be?
3. Science
A man drop a stone of mass 2kg room the top of a building of height 15m when it reaches the ground find its kinetic energy.
4. Science
If a small marble and large marble are hit with the same force which will go farther? Why?
5. Science 6
When you turn on a battery powered flashlight, you transform... A:heat energy into light and chemical energy. B:chemical energy into electrical energy and light. C:heat energy into chemical energy and light. D:eletrical energy and light energy into chemical energy. I think B ...
6. Science
hearing rattles from a snake, a boy make two rapid displacements of magnitude 1.8m and 2.4m in sketches show how the two displacements might add up to give magnitude of
7. Science
When calculating delta Tsample,why is th initial temperature taken to be 100 degrees Celsius
8. Science
Why is the weight of an object less on the moon than on Earth?
9. science
The effects of electricity can be explained by the structure of the _______?
10. Science
A pendulum is made with a bowling ball as the bob and a wire attached to the ceiling, as shown in the illustration below. The person in the illustration pulls the bowling ball back until it touches his nose, then releases the bowling ball. Assume that he does not move. 1....
11. Science
What percentage of the energy from the grass would the hawks get in the trophic level pyramid of a food chain
12. Science
how much work is done on a 50kg cart that is pushed 10m at a constant rate of 5m/s^2
13. Science
A pendulum is made with a bowling ball as the bob and a wire attached to the ceiling, as shown in the illustration below. The person in the illustration pulls the bowling ball back until it touches his nose, then releases the bowling ball. Assume that he does not move. 1....
14. Science
A pendulum is made with a bowling ball as the bob and a wire attached to the ceiling, as shown in the illustration below. The person in the illustration pulls the bowling ball back until it touches his nose, then releases the bowling ball. Assume that he does not move. 1....
15. Science
A pendulum is made with a bowling ball as the bob and a wire attached to the ceiling, as shown in the illustration below. The person in the illustration pulls the bowling ball back until it touches his nose, then releases the bowling ball. Assume that he does not move. 1....
16. Science
A pendulum is made with a bowling ball as the bob and a wire attached to the ceiling, as shown in the illustration below. The person in the illustration pulls the bowling ball back until it touches his nose, then releases the bowling ball. Assume that he does not move. 1....
17. Science
How much power is lifted if a person lifts 60N weight up 2 meters in 10 seconds?
18. science
why dos buying food that is grown in your local area help prevent loss of biodiversity ??????
19. SCIENCE HELP ASAP
1. in an atom, electrons_____ 2. dot diagrams are used to represent_______ 3. the maximum number of electrons in the second energy level of an atom is________
20. Science
The weight of an object is the product of its mass, m, and the acceleration of gravity, g (where g=9.8 m/s2). If an object’s mass is m=58.5 grams, what is its weight? Same goes to 45.93 grams. If you could answer as soon as possible that would be great!
21. Science
An eagle flying along a horizontal path drops a small snake from a height of 6.5 m while travelling 5.0 m/s. How far does the snake travel horizontally before it hits the ground below? G: R: E: S: A:
22. Science
What do we mean when we say, "The speed of the car is 90 km/h."?
23. Science
What is the identity of the precipitate that forms when 70 mL of 0.3 M BaCl2 reacts with 65 mL of 0.35 M Na2CO3
24. physical science B
I have to build a roller coaster with 3 hills. Hill A is 15 inches high,it drops down to 3 inches, rises to 8 inches, drops again to 5 inches and rises a last time to 3 inches before dropping off. My question is when using a tennis ball as the car.. 1. What is the initial ...
25. Science
A car is traveling at 8.9 m/s (20mph) in a school zone. A child darts in front of the car. Ignoring reaction time, the car can accelerate (brake) at -4.57 m/s. -How long will it take for the car to stop? -How far will the car travel in that time?
26. science
Earth's energy sources include both renewable and nonrenewable resources. name at least three sources of energy that could be used in your house. then describe the ideal energy source for generating most of your home's electricity, and explain why you choose that source
27. SCIENCE
A BALL OF MASS 2KG FALLS FROM REST FROM A HEIGHT OF 200M.CALCULATE ITS KINETIC ENERGY AFTER FALLING A DISTANCE OF 50M?
28. Math,science
The 5th term of an arithmetic progression is 23 and the 12th term is 37.find the third term and common different
29. Science
Radioactivity is produced when unstable nuclei___ 1) bond together 2) break apart ***** 3) become cooler 4) expand I need help please
30. science
The question is: Calculate the pH of a solution that results from 50.0 ml of 0.15mol/L HCOOH with 75.0ml of 0.13mol/L HCOONa. I know I need to use the henderson-hasselbalch equation with the pka being 3.74 but I'm not sure how to get the ratio to plug in.
31. Science
A physics student stands in an 64th floor. The students weights 810 N. What is his mass and normal force? Mass is 83? normal force is 810?
32. Science
2. A cable pulls a 15.0 kg crate at constant speed across a horizontal table.The tension in the cable is 60.0 N. 1. What is the frictional force and normal force?
33. Science
1. A truck is traveling 20 m/s to the left and bill is moving at 4 m/s left. If you are in Postion A what velocity do you see bill moving at?
34. science
how do you describe a scale im doing a portfolio and I don't know how too describe a scale please help me!!
35. Science
Air is compressed until a small piece of cotton is ignited. From a standpoint of thermodynamics what is Happening at a molecular level? Energy cant be created of destroyed?
36. Science
An object mass m1 falls from a height of h1. a. Write a formula for the velocity of the object just before it stikes the ground in terms of g,m1,and h1. b. Write a formula for the velocity of the object at the half way point in terms of g,m1, and h1.
37. Science
1. A ball is thrown 15 m/s at an angle of 60. How high does the ball go? 2. A ball rolls off a table going 8 m/s. If the table is 1.8 m tall, how far away does the ball land?
38. Science
A student rides his bike off the roof of the high school horizontally at 8 m/s that is 12.5 m high. 1. How far from the base does the object land? 2. What is his y-direction velocity just before it strikes the ground?
39. science
why is the use of fossil fuels not a long term solution to the worlds energy needs.
40. science
What is the momentum of a 20.0 kg scooter traveling a 5.00 m/s?
41. science
this is a follow up question from my last one with the exact question If you dissolve 200 g of salt in 20 l of water, what is the density of that solution of salty water? Hint: In this particular example, assume that the total volume doesn’t change when salt is added to ...
42. Math science
A camp has food stock for 500 people for 70 days.if 200more peole join tha camp how long will tha stock last
43. science
If I dissolve 200g in 20 litre of water what is the density of the salty water. please help
44. science
According to the periodic table, all of the following are metals except ? A) Sodium (Na) B) Zinc (Zn) C) Fluorine (F) D) Calcium (Ca)
45. science
1. Which is not a characteristic of the group 1 alkali metals? A. High densities B. Low melting points C. Found in batteries D. Silvery solid 2. which of the following is true of the group 2 alkali earth metals A. they are less dense that the group 1 alkali metals b. They have...
46. Science
Which of these is found inside the solar system? A) Moon B) Nebula C) Galaxy D) Black hole
47. chemistry, science
how many moles of he atoms are there in 0.02g of he?
48. science
an electron is projected horizontally at a speed of 3x10^6 m/s into a uniform electric field 200 N/C produced by two charged plates of width 0.1m (a) find the a cceleration of the electron in the elec field.(b) finn the time takes to travel through the electric field.(c) what ...
49. Science
Which material is the densest air,water,plastic,or iron
50. Science
Do light and sound travel at the same speed through solids, liquids, and gasses? What are the effects of light and sound traveling through different objects?
51. Science
4.9 gm of H2SO4 is mixed with Water to form 5 litres of aqueous solution. Findits concentration. (Molecular weight of H2SO4 is 98 gm/mole)
52. Science
1. The line on the graph below represents an object that is: A: Moving at a constant speed B: Increasing its speed C: Decreasing it's speed D: Not moving at all 2. To determine the acceleration of an object moving in a straight line, you must calculate the change in its speed ...
53. Science 6
during the process of photosynthesis, plants convert carbon dioxide and water into glucose. Covalent bonds hold the glucose molecules together. the energy stored in these covalent bonds is called? A:nuclear energy. B:thermal energy. C:electrical energy. D:chemical energy. I ...
54. Engineering Science N4
A box of books has a mass of 46kg and is being towed by a rope which is oriented at 15 degree to the horizontal at a point where it is tied into a knot. If the pulling force is increased until the box begins to slide, determine the box's initial acceleration if the coefficient...
55. Science
CeCl3 is having Ca conntent 12 g/L,If we try to pricipitate Ce2(CO3)by using 1.0M Na2CO3,what is the Ca impurity level in the fianl Ce carbonte and how much pH we have to maintain to control Ca imprurity in the final out put?
56. Science
Calculate the time needed for a net force of 5N to change the velocity of a 10kg mass by 2m
57. Science
How do the spaces between particles affect viscosity?
58. Science
How did Rutherford come to the conclusion that most of the space in atoms is empty?
59. Science- Earth
Under which circumstances do neap tides occur? HELP NEED ASAP!!
60. science
1. When Mendeleyev arranged the elements into the periodic table, he found that elements with fell into groups on the table A. the same mass B. similar size C. Similar properties D. The same color 2. Every element has its own atomic number. The atomic number is the number of ...
61. Science
Describe th flow of blood in the human body, including through each of the four chambers of the heart. Explain how the blood changes as it moves on locations in the body i have been stuck on this for almost 3o minutes i need help :)
62. science
Consider a point charge with q = 1.510-8 C. (a) What is the radius of an equipotential surface having a potential of 30 V? (b) Are surfaces whose potential differ by a constant amount (1.0 V) evenly spaced in radius
63. Science HELP!!! FAST!!!
24. Many people who care about conserving natural resources would choose to use wind energy to power their homes. However, wind power is not an option for people in many parts of the country. Explain what the benefits of wind power are and why it is not available to everyone ...
64. science
A solid weighs 100g in air,75g in water and 70g in oil.Calculate the relative density of oil.
65. social science
which places or countries are located at 20 degrees south and 20 degrees east?
66. Science
How are the primary pigments related to the primary colors? The primary pigments are: A. Complementary to the primary colors B. Associated with the primary colors C. Unrelated to the primary colors
67. science
calculate the amount of nitrogen required for making 70g of ammonia
68. Science
What is a natural satellite?
69. Science
What are constellations?
70. Science
Do all the stars in the sky move? Explain
71. Science
What animal is on top of the food chain
72. Science
Are euglena unicellular or multicellular? They are unicellular
73. Science
If a nickel is dropped from a building and no air resistance is present,how does the energy of the nickel change?
74. Science
If a nickel is dropped from a building and no air resistance is present,how does the energy of the nickel change?
75. Science
What chemical equation would represent methane (CH4) burning in the presence of oxygen gas (O2) to form water and carbon dioxide? (Make sure it's balanced)
76. science
you added 2ml of protein, 3ml of water, and 4ml of dye. how will you prepare blank for the experiment
77. science
A car travels 70km on 20 litre of petrol.How far could that car travels on 230 litres of petrol
78. science
if a dentist chair weighs 1600N and is raised by a large piston with a cross sectional area 75.0cm2, what force must be exerted on a small piston of crosssectional area 3.75cm2 to lift the chair
79. Science
You have been challenged to lift a weight of 200 kg from the floor.Your challenger has the same task and also lifts a 200 kg from the floor but they take longer time to do so.Who has completed more or less work?Explain.Who has used more power?Why?
80. Science
1. Which of the following is an example of matter A.Leaves B.Shadows C.Light from the sun D.Sound<--- 2.Which of the following IS an Example of a chemical property of matter A.ability to melt B.ability to frezze<--- C.Ability to Break D.Ability To React 3. The physical ...
81. Science
You have been challenged to lift a weight of 200 kg from the floor.Your challenger has the same task and also lifts a 200 kg from the floor but they take longer time to do so.Who has completed more or less work?Explain.Who has used more power?Why?
82. Science
How many moles of mercury will be produced by electrolyzing 1.0M Hg(NO3)2 solution with a current 2.00A for 2 hours.
83. science
A gardener holds a hose 0.75m above the ground such that the water shoot out horizontally and hits the ground at a point 20m away.What is the speed with which the water leaves the hose?
84. Science
density of wood that is 20 cm below water and 60 cm above water
85. science
what are all the types of clouds
86. physical science
How many minutes would be required for a 310.0 W immersion heater to heat 202.0 g of water from 22.0°C to 95.6°C?
87. Physical Science
MH = 16.32 g/kg SH = 9.86 g/kg Air mass temperature = 15° C (59° F) What is the Relative humidity & the approximate Dew-point temperature? How do i set this problem up? I do not understand. Thanks
88. material science
What is the ratio of the maximum axial stress to the maximum bending stress in the inclined cell walls of hexagon honeycombs in terms of t,h ,l, and theta?
89. Science
What is methanol?
90. science
a body is released from the great height and falls freely towards the earth . another body is released from the same height , one second later . then the separation between the two bodies , two seconds after release of the second body is
91. science
Taking the resistivity of platinoid as 3.3 x 10-7 m, find the resistance of 7.0 m of platinoid wire of average diameter 0.14 cm.
92. science
writing balanced chemical reaction of K2CO3 (s) with HCl (aq)??
93. Computer science
Final project Which is currency converter by camera from € to £ for example And not need to be perfect program so simple as my teacher told me and by java language So its like making an application then write the report 6300 around that
94. SCIENCE
Calculate the mass of caco3 required to liberate 10liters of co2 at stp?
95. Science
Ammonia may be oxidised to nitrogen monoxide in the presence of a catalyst according to the following equation. 4NH3 +5O2-4NO+6H2O.If 27 litres of reactants are consumed ,what volume of nitrogen monoxide is produced at the same temperature and pressure?
96. Math
Rachel answer 20 out of 25 questions correctly on her science test what percent of the questions did she answer correctly
97. science, chemistry
Lead metal is added to 0.150 M Cr3+(aq). Pb(s)+2Cr3+(aq)⇌Pb2+(aq)+2Cr2+(aq). KC=3.2×10−10 What is [Pb2+] when equilibrium is established in the reaction? What is [Cr2+] when equilibrium is established in the reaction? What is [Cr3+] when equilibrium is established in the ...
98. physical science
A uniform stripe of eureka (resistivity 5-0 × 〖10〗^(-7) Ωm) has a resistance of 0.80 Ω per metre and is 0.25 cm wide. What is its thickness? (show work)
99. physical science
A block of carbon, 1.0 cm by 2.0 cm by 5.0 cm has a resistance of 0.80 Ω between its two smaller faces. What is the resistivity of carbon? (show work)
100. physical science
. The maximum allowable resistance for an underwater cable is one hundredth of an ohm per metre. If the resistivity of cooper is 1.54 × 〖10〗^(-8) Ω m, find the least diameter of a copper cable that could be used (show work)